The field of the present invention pertains to computer implemented graphics. More particularly, the present invention relates to a system and method for implementing high fidelity multichannel computer graphics displays.
Many computer implemented applications interact with and present information to a user via graphical means. Some of the most compelling such applications involve visual computing/data visualization, whereby information and interaction with the user is accomplished through the use of large graphical displays. For example, applications have been created which graphically depict information stored within a database (e.g., information describing an underground oil field) allow the user to interact with the information in real-time, visually, by xe2x80x9cmovingxe2x80x9d through a xe2x80x9cvirtualxe2x80x9d representation of the information stored within the database (e.g., popularly known as xe2x80x9cvirtual realityxe2x80x9d).
These applications typically require large, high fidelity displays for their most compelling implementation. For example, a powerful visual computing system might include a very large wrap-around screen for graphically presenting data/information to one or more users. The large wrap around screens allow the creation of an extremely realistic, compelling, virtual representation of the information to the one or more users, allowing them to realistically xe2x80x9cnavigatexe2x80x9d through any virtual 3D environment, such as, for example, xe2x80x9cwalkingxe2x80x9d through the rooms of a newly designed building, xe2x80x9cflyingxe2x80x9d over a large terrain data base of geo-specific data, or the like.
Accordingly, virtual reality, advanced CAD, and other similar advanced visual computing applications require large high fidelity graphics displays for effective implementation. As is well known in the art, the creation of large graphics-type visual displays in a manageable and cost efficient manner has proven problematic. One commonly used method of generating a large display is to combine multiple (e.g., two or more) smaller screens, or visual channels, into a single larger display. This type of display is referred to as a multichannel display, since the single larger image is created through the combination of two or more smaller images.
Prior art FIG. 1 shows a diagram of a typical large multichannel display system 100. System 100 includes three smaller screens (e.g., 20 feet by 30 feet), screen 101, screen 102, and screen 103, that are combined to form a single very large display (e.g., 20 feet by 90 feet). Areas 110 and 110 show the junctions between the screens. Screens 101-103 function coherently in order to create the large display (e.g., 20 feet by 90 feet) seen by a group of users 105. In this implementation, screens 101-103 are projection type screens, with the images projected from an image projector 130. Image projector 130 receives video information from an image generator 132 via a blender 131.
To ensure fidelity, the edges between the channels of screens 101-103, xe2x80x9cblend regionsxe2x80x9d 110 and 111, need to blend seamlessly in order to create the large image. This has proven problematic. As with most arrayed multichannel displays, the edges of the combined channels must be blended such that the xe2x80x9cseamsxe2x80x9d are as unnoticeable as possible. In projection type multichannel displays (e.g., system 100), one typical prior art approach is to overlap the edges of the image from each video feed in order to create a smooth transition from the image of one channel to the next, in order to smooth the seams of areas 110 and 111. This requires some overlap of the video from each image and requires that the brightness of one image reduces as the other increases in the overlap region, areas 110 and 111. To maintain high fidelity, the brightness levels of the channels need to be precisely controlled. However, achieving this level of control often requires the incorporation of expensive, dedicated hardware within image generator unit 130.
Prior art FIG. 2 shows system 100 in greater detail. As depicted in FIG. 2, the image generator 132 includes graphics computers 241-243 for generating the video information for each video channel. Computers 241-243 are respectively coupled to image blenders 251-253, which are in turn coupled to projectors 201-203. Projectors 201-203 function by projecting the video information received from computers 241-243 and image blenders 251-253 onto their respective one of screens 101-103.
As described above, to maintain high fidelity, the seams of blend regions 110 and 111 need to be precisely blended such that they are as unnoticeable as possible. System 100 includes dedicated image blenders 251-253 for performing the precise brightness control required to implement the seamless overlap of screens 101-103. Computers 241-243 include graphics processing hardware and software and function by generating the video information for each respective channel for screens 101-103. Blenders 251-253 perform brightness processing on the video information received from computers 241-243.
With system 100, and other similar prior art multichannel display systems, the blending function is performed by the dedicated image blenders 251-253. Image blenders 251-253 are dedicated, special purpose hardware components which process the video information emerging from computers 241-243. The image blenders 251-253, as is typical with prior art multichannel display systems, are format/hardware implementation specific, in that they are not readily interchangeable among display systems from different manufacturers. Because of the required level of fidelity, image blenders 251-253 are relatively complex and expensive, adding significantly to the overall complexity and cost of system 100.
Thus, what is required is a method and system for implementing high fidelity blending for multichannel displays without requiring the use of a dedicated blending hardware for post-image generation blending processing. What is required is a system which can be efficiently implemented on multiple computer system platforms. The required system should be inexpensive, and not require additional, dedicated hardware for its implementation.
The present invention is a method and system for implementing high fidelity blending for multichannel displays without requiring the use of a dedicated blending hardware for processing video information after it emerges from an image generator. The present invention provides a system which can be efficiently implemented on multiple computer system platforms. The system of the present invention is inexpensive, and does not require additional, dedicated hardware for its implementation.
In one embodiment, the present invention is implemented as an edge blending process executed on a graphics computer system included within the image generator. The computer system included within the image generator performs the edge blending processing on the gamma-corrected image before it is taken from the frame buffer or sent to video. This eliminates the need for a separate dedicated blending hardware unit, as required with prior art multichannel display systems. The computer systems included within the image generator perform the edge blending processing on each of the video frames of the channels such that as the video information emerges from the image generator each of the video frames includes the necessary blending required for creating a seamless multichannel display.
The blending process of the present invention occurs as the information is being rendered by the computer systems. For example, As a left computer generated frame is rendered for display on a first video channel, a calculated blend geometry is rendered onto that frame to modulate the brightness in the blend/overlap region, resulting in a first blended frame. This occurs before the frame is sent to video. As a right frame is rendered for display on a second channel, a second complimentary blend geometry is rendered onto the second frame to modulate the brightness of the second frame in the blend/overlap region, resulting in a second blended frame. The overly regions of these blended frames have their respective brightness levels modulated such that when the first and second blended frames are sent to video and projected onto adjacent first and second screens, the resulting images overlap within the overlap regions and combine such that the first and second overlap regions precisely align. In this manner, the image from the first blended video frame and the image from the second blended video frame form a seamless junction between the two, thereby implementing a high fidelity multichannel display.